The present invention deals broadly with the field of windows. More specifically, however, the invention applies to a window, such as double-hung window, wherein a sash slides within a frame. The specific focus of the invention is structure employed to effect retention of the window sash within the frame at an intended location along an axis perpendicular to a plane defined by the window frame within which the sash slides.
The prior art includes many types of windows which are employed to bring light into a building. One type of window known in the prior art is a double-hung window. Such a window typically employs two vertically movable sash assemblies, each carrying its own pane of glass, which are movable, typically, vertically within the frame.
Opposed, inwardly facing lateral portions of the frame. are typically provided with a balance tube which includes appropriate structure to render the window sashes more safe. Balance mechanisms are employed within the balance tube in order to deter undesirable, unintended slamming of a sash such that injury could result.
It is also desirable, however, that the sashes be able to be tilted inward or removed for cleaning of the glass portions of the sash assemblies. Various mechanisms have been employed to release a sash from a position which it is intended to occupy within the frame. Typically, a sash is desired to be located at a position along an axis, generally perpendicular to a plane defined by the frame, for sliding movement along that position. Various types of structures have been utilized to effect maintenance of a sash in the desired position yet allow it to be tilted inward or removed for cleaning. One such structure utilizes a pair of laterally extending latch mechanisms carried by the sash. The latch mechanisms move linearly along an axis through the sash and into the frame. One latch mechanism extends laterally on one side of the sash and a second latch mechanism extends laterally on the other side of the sash. When it is desired to remove a sash, the sash is moved to an intended vertical release location, and the person removing the sash releases one latch with one hand and the other latch with the other hand. The sash is then tilted or slid out of its normal position and removed from the frame for cleaning. Such a structure has a number of drawbacks. One is that the person removing the window sash needs full availability of both hands to effect release of the latches. Attempts have been made to solve this problem by designing a unitary assembly for concurrently releasing both latches (that is, for simultaneously effecting retraction of the latches). While some measure of success has been achieved with these attempts, other problems still exist. For example, linearly moving latches typically do not provide fully adequate definition of structure for sliding of a sash along an intended track and adequate resistance to pressures which might tend to dislodge a sash from the window frame. One reason for the inadequate resistance to dislodgement is the relatively small cross-section of a latch mechanism extending from the sash.
It is to these dictates and shortcomings of the prior art that the present invention is directed. It is a position maintenance mechanism which addresses these dictates and problems and provides solutions which make the invention a significant over prior art apparatuses.
The present invention is apparatus which functions to maintain a sliding window sash at an intended position along an axis which is generally perpendicular to a plane defined by a frame within which the sash slides. The frame has an inwardly facing surface which, when the sash is in an intended position at which it slides within the frame, is opposite an outwardly facing surface of the sash. The apparatus in order to maintain the sash at such an intended position includes means to define an elongated trough formed in the inwardly facing surface of the frame. The trough extends generally parallel to the plane defined by the frame and generally in the direction of intended sliding of the sash. The apparatus further includes a blade which defines a plane and means to mount the blade within a cavity in the sash. The blade is mounted and oriented with the plane defined thereby generally parallel to the plane defined by the frame. The blade is disposed within the sash for pivotal movement between a first position and a second position. In the first position of the blade, it is retracted within the outwardly facing surface of the sash and does not extend outwardly beyond the surface of the sash. In its second position, the blade is extended beyond the outwardly facing surface of the sash and into the trough. Means are provided to normally bias the blade to the second position thereof, and means are provided to allow selective retraction of the blade to its first position.
It is intended that the blade, when it is in its second position received within the trough, will be extended fully into the trough to engage a bottom thereof. In a preferred embodiment, the bottom of the trough has a slot formed therein. The location of the slot along the bottom of the trough is such that, when the sash is in a closed position, the blade is at a position coextensive with the slot and extends into the slot. The pivotal disposition of the blade wherein it is extended into and through the slot in the bottom of the trough is defined as a third position of the blade.
In the preferred embodiment, the blade includes an edge which is angled such that, as the sash is moved from a closed position to an open position, the angled edge engages an end of the slot and ramps the blade up and out of the slot. Such action facilitates retraction of the blade from its third position to its second position.
The blade is disposed for pivoting about an axis which is generally perpendicular to the plane defined by the window frame. It is envisioned that a coil spring would be employed to bias the blade about such an axis outwardly through, and away from, the outwardly facing surface of the sash to its second and third positions.
The preferred embodiment contemplates employment of a linearly moving actuator to effect retraction of the blade within the outwardly facing surface of the sash. Such an actuator would be operatively connected to the blade to overcome the biasing of the blade to its second and third positions, and would effect rotation of the blade in a direction opposite that in which the coil spring biases the blade.
A preferred embodiment of the invention includes a wire yolk which is attached to the blade and a length of cord which is attached to the yolk. The cord extends away from the yolk and is attached to a driver for drawing the length of cord inwardly with respect to the outwardly facing surface of the sash to effect rotation of the blade against the biasing means.
It is envisioned that an end plate assembly would be provided for cooperation with the sash, the end plate assembly including a face plate mounted generally flush with the outwardly facing surf ace. The end plate assembly would include a pair of generally parallel tabs extending inwardly from the face plate. The tabs, it is intended, would have oppositely facing surfaces, each of these surfaces mounting a stub axle which is substantially coaxial with a stub axle on the facing surface of the other tab. The two-stub axles would extend toward each other so as to be received within an aperture in the blade, the aperture sized and shaped to receive the stub axles.
Each of opposite sides of the blade defines a ramp surface. When the blade is inserted between distal ends of the stub axles, the ramp surfaces increasingly urge the distal ends of the stub axles apart until the distal ends become registered with the aperture. They then snap into the aperture to effect mounting of the blade.
In practice, a sash configured in accordance with the invention would very likely employ means defining an elongated trough in each of oppositely facing inward surfaces of the frame. Each of said troughs would extend generally parallel to the plane defined by the frame and generally in a direction of intended sliding of the sash. Each of such troughs would be intended to receive one of a pair of blades which define a generally common plane. Each of the pair of blades (see, for example, FIG. 8) which define a generally common plane. Each of the pair of blades would be mounted within a corresponding cavity in the sash and oriented with the plane defined by the blades generally parallel to the plane defined by the frame. As in the case of the structure previously described, each blade would be disposed for pivotal movement between a first position, wherein the blade is retracted within a corresponding outwardly facing surface of the sash, and a second position, wherein each of the blades is extended into a corresponding trough in an inwardly facing surface of the frame which is opposite the outwardly facing surface of the sash within which the cavity in which the blade is mounted is formed. The blades would normally be biased to their second positions in engagement with the bottom of the troughs, and means for selectively retracting the blades to their first positions would be provided.
With the dual blade embodiment, means would be provided to effect retraction of the blades from their second positions to their first positions simultaneously. The invention envisions a common member for effecting concurrent retraction of the blades.